Finding the Fourth Proportional to 9,411.56, 12,988.18 and 5,220.12

Step by Step Solution

1. Step 1: Write the proportion equation
   9,411.56 : 12,988.18 = 5,220.12 : x
2. Step 2: Convert to fraction form
   9,411.56/12,988.18 = 5,220.12/x
3. Step 3: Cross multiply
   9,411.56x = 12,988.18 × 5,220.12
4. Step 4: Simplify right side
   9,411.56x = 67,799,858.18
5. Step 5: Solve for x
   x = 67,799,858.18/9,411.56
6. Step 6: Final answer
   x = 7,203.89